The present invention relates to couplers used to secure attachments such as buckets, air-operated hammers, shears, etc. fixedly and operatively to the distal end of a arm of a tractor, backhoe, excavator or other type of arm-equipped construction/agricultural equipment. As is generally well known, couplers are used as an alternative to a pin-on connection for fixedly and operatively securing an implement to the distal end of an arm which is, in turn, secured to a boom of a construction/agricultural machine such as a backhoe or excavator.
Spread-style couplers are generally known. These couplers are connected to an arm by a pin-on connection at a first pivot point and are connected to a control link by a pin-on connection at a second pivot point. These prior couplers include front and rear hooks that open in respective opposite directions oriented outwardly away from each other. Each hook is pivotably connected to the body of the coupler, i.e., each hook pivots about a separate axis. In use, the hooks are collapsed toward each other are placed between front (first) and rear (second) pins of a bucket or other attachment and the hooks are then spread-apart from each other, using a screw jack or other means. Upon being spread sufficiently far apart, the rear hook engages the rear pin of the implement and the front hook engages the front pin of the implement which results in the implement being operatively connected to the arm.
Known spread-style couplers are deficient for many reasons. One notable disadvantage of known spread-style couplers is that both hooks pivot relative to the coupler body. This results in an excessive amount of pivot points and reduces the strength of the coupler. Similarly, during digging and other operations, large loads are exerted upon the rear hook (inwardly located toward the boom-equipped machine) and the pivotable nature of this hook is not a desirable trait to encounter these large loads. Another deficiency of these known couplers results from the fact that the pivot points of the hooks are not coincident with the pivot points where the coupler is pinned to the arm and control link.
In light of the foregoing, a need has been identified for a new and improved spread-style coupler that overcomes the foregoing deficiencies and others while providing better overall results.